Electric pushbutton switch

ABSTRACT

A pushbutton switch comprising a casing and a base mounted therein for relative movement. The base has thereon a submagnetic pole plate and a Hall element for electrical connection to a switching element. A magnet is mounted in the casing in radial alignment with the Hall element and the pole piece whereby, upon relative movement between the casing and the base, the polarity of the voltage across the Hall element is varied to thereby actuate the switching element. A second magnet is mounted on the base in axial alignment with the first magnet so as to normally hold the latter and the casing floating in the air by virtue of the magnetic repulsing force.

United States Patent Appl. No. Filed Patented Assignee Priority ELECTRICPUSl-IBUTTON SWITCH 7 Claims, 4 Drawing Figs. U.S. Cl. 335/2, 335/205,335/207 Int. Cl H0lh 3/00 Field of Search 200/63; 335/2, 209, 205, 206,207

Primary Examiner-G. Harris Attorney-Chittick, Pfund, Birch, Samuels &Gauthier ABSTRACT: A pushbutton switch comprising a casing and a basemounted therein for relative movement. The base has thereon asubmagnetic pole plate and a Hall element for electrical connection to aswitching element. A magnet is mounted in the casing in radial alignmentwith the Hall element and the pole piece whereby, upon relative movementbetween the easing and the base, the polarity of the voltage across theHall element is varied to thereby actuate the switching element. Asecond magnet is mounted on the base in axial alignment with the firstmagnet so as to normally hold the latter and the casing floating in theair by virtue of the magnetic repulsing force.

ELEMENT 5 SWITCHING FIG.3

HALL ELEMENT INVENTOR TOSHIO MOGI RA m ilm- Background of the InventionThe present invention relates to an electric switch and, moreparticularly, to a contactless electric pushbutton switch adapted foruse with a switching element such as a thyristor or a transistor.

A conventional electric pushbutton switch usually employs a pair ofcontacts which are liable to become damaged in relatively shorteroperative time for the reasons self-explanatory to those skilled in theart. It is, therefore, a primary object of the present invention toprovide a contactless electric pushbutton switch.

Nowadays, a Hall element is well known to have such an operativecharacteristic that the polarity of the electrical voltage across theelement is varied with the variation in the polarity of the magneticfield applied to the element. It is, therefore, a secondary object ofthe present invention to provide a contactless electric pushbuttonswitch which utilizes such characteristic of a hall element.

It is a further object of the present invention to provide a contactlesselectric pushbutton switch of the class specified in the precedingparagraph and which utilizes a simple arrangement so as to cause theHall element to perform such characteristic as above stated.

It is a still further object of the invention to provide a pushbuttonswitch of the class which is specified in the above and which does notnecessarily require mechanical biasing means such as a spring so as toautomatically restore, after each depression or actuation, the switch toits initial position.

SUMMARY OF THE INVENTION According to the present invention, there isprovided an electric pushbutton switch comprising a first member, asecond hollow member receiving said first member for relative slidingmovement between first and second positions, magnet member mounted onone of said first and second members, a submagnetic pole plate mountedon the other of said first and second members is opposite relationshipto said magnet member, said submagnetic plate having a Hall elementmounted on the surface thereof facing said magnet member, said Hallelement having its terminals adapted to be electrically connected to aswitching element, and means for normally holding said one member andsaid magnet member in said first position, the arrangement being suchthat, when said one member is in said first position, one of themagnetic poles of said magnet member is positioned in oppositerelationship to said Hall element and, when said one member is movedagainst said holding means to said second position, the other magneticpole of said member is positioned in front of said Hall element.

Preferably, the said holding means may be a second magnet member mountedon the said the other member in axial alignment with the first saidmagnet member. The first and second magnet members may advantageously beso arranged that the poles of both magnet members which are disposed infacing relationship to one another are of the same polarity so that therepulsing force therebetween is operable to normally hold said onemember and said first magnet member in said first position. Thesubmagnetic plate may advantageously extend the entire distance overwhich the first magnet member is reciprocally moved relative to the Hallelement for the reason which will become apparent later. The relativemovement between the first and second members is guided and limited byguide means which may preferably comprise a projection on one of thefirst and second members and an elongated groove formed in the other ofthe members, the projection being engaged in said groove for relativesliding movement. The said first member may be a base or a holder havingan axial fiat surface on which the submagnetic plate and the Hallelement are mounted and a transverse fiat surface or a shoulder to whichthe second magnet member is secured. The said second member may be asubstantially cylindrical casing having a closed top and adapted to bepressed down for the actuation of the pushbutton switch, an openedbottom end through which the base extends outwardly when the casing isin its said second position, and an inner surface on which the firstmagnet is mounted in axial alignment with the second magnet member.

The above and other objects and features of the present invention willbecome apparent from the following description of a preferred embodimentof the invention with reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a circuit diagramillustrating the principle of the present invention;

FIG. 2 is a longitudinal sectional view of an embodiment of the electricpushbutton switch according to the present inventron;

FIG. 3 is a similar view to FIG. 2 but illustrating the components ofthe switch in different or moved positions; and

FIG. 4 is a cross-sectional view of the switch taken along line IV-IV inFIG. 2.

DESCRIPTION OF A PREFERRED EMBODIMENT Reference will be made first toFIG. I of the drawings showing a circuit diagram which illustrates theprinciple of the present invention. The circuit shown includes a Hallelement 1, a power source 2 and a resistor 3. A switching element 4,such as a transistor or thyristor, is electrically connected to the Hallterminals of the Hall element 1. With this arrangement, when a magneticfield B is applied from above the surface of the drawingsperpendicularly down to the Hall element I, the latter is actuated tofeed a negative voltage to an input terminal 5 of the switching element4 while a positive voltage is fed to the other input terminal 6 of theelement 4. On the other hand, if a magnetic field B is applied frombehind the surface of the drawings perpendicularly up to the Hallelement 1, a positive voltage is supplied to the input terminal 5 of theswitching element 4 while a negative voltage is given to the inputterminal 6 thereof. It is known that the polarity of the voltage acrossa Hall element is varied with the variation in the polarity of themagnetic field applied to the Hall element in the aforestated manner.

The present invention utilizes a reciprocal movement of a magnetmemberrelative to the Hall element I so as to cause the latter toperform the above-stated characteristic. The pushbutton switch accordingto the present invention will be more specifically described withreference to FIGS. 2 and 4 of the drawings which illustrate theconstruction of an embodiment of the invention.

A generally cylindrical base or holder 7 is mounted in a cylindricalhollow casing 8 for relative reciprocal sliding movement in axialdirection with respect to one another. The casing has a closed top endand an open bottom end as shown. The relative movement is guided andlimited by means of an axial elongated groove 9 formed in thecylindrical side face of the holder 7 and a pin 10 mounted on the innersurface of the casing 8 and projecting radially inwardly into the groove9. In 1 the illustrated embodiment of the invention, the holder 7 isformed therein with a fiat axial surface 1! and a fiat transversesurface I2 extending radially outwardly from the bottom end of thesurface 11 substantially at right angles with respect to the surface 11to form a shoulder on the holder 7. A flat submagnetic pole plate 11 issecured to and extends over the entire length of the axial surface I].The Hall element 1 is mounted on the exposed surface of the submagneticpole I l.

A permanent magnet 13 is preferably secured to the shoulder of theholder 7. More specifically, the transverse flat surface 12 is formedtherein with a recess in which the magnet I3 is fitted in such a mannerthat one of the extends in the same plane as the surface 12. Anothergenerally U-shaped magnet 14 is mounted on the inner surface of thecasing 8 in axial alignment with the magnet 13 and also in oppole facesthereof nun...

posite relationship to the plate 11'. The magnet 14 has one magneticpole 15 which is disposed in opposite relationship to the transversesurface 12 and which is of the same polarity as the pole 16 of themagnet 13 facing the magnet 14. In the illustrated embodiment, theopposite magnetic poles l5 and 16 of the magnets 14 and 13 are bothnorth (N) poles which are in repulsing relationship to one another.

By virtue of this repulsing force, the casing 8 is held floating in theair, as will be seen in FIG. 2. When the casing 8 is pushed down in thedirection indicated by an arrow A against the repulsing force, thecasing has a sliding downward movement relative to the holder 7 asviewed in the drawings. This relative movement is guided and limited bythe guide means which, as stated in the above, comprise the groove 9 inthe holder 7 and the pin 10 mounted on the inner surface of the casing 8and engaging with the groove. The assembly is arranged such that, whenthe assembly is in its rest or inoperative position illustrated in FIG.2, i.e., when the casing 8 is held floating in the air by virtue of theabove-mentioned repulsing force, the pole face of the bottom side poleof the magnet 14 is positioned in opposite relationship to the Hallelement I mounted on the submagnetic plate 11' so that the magnetic fluxfrom the magnetic pole 15 is applied to and passes through the Hallelement 1 and then through the submagnetic plate 11' to the othermagnetic pole 17 of the magnet 14 whereas, in the position of theassembly in which the casing 8 is fully moved in the direction of thearrow A against the repulsing force, as shown in FIG. 3, the pole faceof the other pole 17 of the magnet 14 is positioned in front of the Hallelement 1.

Now, a description will be made with respect to the operation of thepushbutton switch described hereinabove. When the pushbutton is in itsFIG. 2 position in which the Hall element is positioned in oppositerelationship to the pole 15 of the magnet 14, a voltage of a certainpolarity is generated at a Hall terminal (not shown) of the Hallelement 1. For the conveniences sake of description, it is assumed thatsaid certain polarity is positive one. On the other hand, when thecasing 8 is depressed down to its FIG. 3 position in which the Hallelement 1 is positioned in front of the other pole 17 of the magnet 14,a voltage of the reversed polarity, i.e., the negative one, is generatedat the terminal of the Hall element 1. Moreover, when the pressure forcewhich has been exerted to the closed end of the casing 8 is removed awaytherefrom, the casing is returned to the position shown in FIG. 2 by therepulsing force between the magnetic poles 15 and 16. It will beappreciated that, through a single reciprocal movement of the casing 8relative to the holder 7, the polarity of the voltage across theterminals of the Hall element 1 is first reversed from and then restoredto the initial polarity. Thus, the pushbutton switch according to thepresent invention can be used as means for producing switching signalsto the switching element 4, such as thyristor or transistor. It willalso be appreciated that the period of time during which the casing 8 iskept depressed as shown in FIG. 3 corresponds to the duration of aswitching signal by which the switching element is actuated.

According to the above-described and illustrated embodiment of theinvention, since the Hall element 1 is provided on the submagnetic platewhich extends the entire distance over which the magnet 14 isreciprocally moved with respect to the Hall element 1, the magnetic fluxfrom the magnet 14 is conveniently distributed over the submagneticplate 1 l This will ensure that there is caused no variation in thereluctance to the magnetic flux, with a resultant advantage thatdemagnetization of the magnet 14 is prevented or at least minimized.Moreover, the pushbutton switch according to the present invention canhave a prolonged operative life because it employs no contact, as statehereinbefore.

In the aforedescribed and illustrated embodiment of the invention, themagnet 13 only is employed to hold the casing 8 and the magnet 14floating in the air by virtue of the magnetic repulsing force producedbetween the magnetic poles 15 and 16. If necessary, however, thoseskilled in the art may easily think of the use of mechanical biasingmeans such as spring either in addition to or in substitution for themagnet 13. It will also be appreciated that, although a selected one ofthe casing 8 and the holder 7 may serve as an actuator for the switchand the other may be mounted on an appropriate support (not shown), theholder 7 may advantageously be secured to such a support because theholder has mounted thereon the Hall element 1 to which electricalconductors are connected.

What is claimed is:

1. An electric pushbutton switch comprising a first member, a secondhollow member receiving said first member for relative sliding movementbetween first and second positions, a magnet member mounted on one ofsaid first and second members, a submagnetic pole plate mounted on theother of said first and second members in opposite relationship to saidmagnet member, said submagnetic pole plate having a Hall element mountedon the surface thereof facing said magnet member, said Hal] elementhaving its terminals adapted to be electrically connected to a switchingelement, and means for normally holding said one member and said magnetmember in said first position, the arrangement being such that, whensaid one member is in said first position, one of the magnetic poles ofsaid magnet member is positioned in opposite relationship to said Hallelement and, when said one member is moved with respect to said theother member against said holding means to said second position, theother magnetic pole of said magnet member is positioned in front of saidHall element.

2. An electric pushbutton switch as defined in claim I in which saidholding means comprise a second magnet member mounted on said the othermember in axial alignment with the first said magnet member, said firstand second magnet members having their adjacent magnetic poles which areof the same polarity so that the repulsing force between said adjacentmagnetic poles is operable to normally hold said one member in saidfirst position.

3. An electric pushbutton switch as defined in claim 2 in which saidsubmagnetic pole plate extends the entire distance over which said firstmagnet member is reciprocally moved relative to said Hall element onsaid pole piece.

4. An electric pushbutton switch as defined in claim 3 furthercomprising means for guiding and limiting said relative reciprocalmovement between said first and second members.

5. An electric pushbutton switch as defined in claim 4 in which saidguiding and limiting means comprise a projection on said one member andan elongated groove formed in said the other member, said projectionbeing in slidable engagement with said groove.

6. An electric pushbutton switch as defined in claim 5, characterized inthat said first member is a base having an axial flat surface on whichsaid pole piece and said Hall element are mounted and a transverse flatsurface to which said second magnet member is secured, and that saidsecond member is a substantially cylindrical casing having an innersurface on which said first magnet member is mounted.

7. An electric pushbutton switch as defined in claim 6 in which saidcasing has a closed end adapted to be pressed down for the actuation ofsaid pushbutton, said base being adapted to be mounted on a support.

* II! i l

1. An electric pushbutton switch comprising a first member, a secondhollow member receiving said first member for relative sliding movementbetween first and second positions, a magnet member mounted on one ofsaid first and second members, a submagnetic pole plate mounted on theother of said first and second members in opposite relationship to saidmagnet member, said submagnetic pole plate having a Hall element mountedon the surface thereof facing said magnet member, said Hall elementhaving its terminals adapted to be electrically connected to a switchingelement, and means for normally holding said one member and said magnetmember in said first position, the arrangement being such that, whensaid one member is in said first position, one of the magnetic poles ofsaid magnet member is positioned in opposite relationship to said Hallelement and, when said one member is moved with respect to said theother member against said holding means to said second position, theother magnetic pole of said magnet member is positioned in front of saidHall element.
 2. An electric pushbutton switch as defined in claim 1 inwhich said holding means comprise a second magnet member mounted on saidthe other member in axial alignment with the first said magnet member,said first and second magnet members having their adjacent magneticpoles which are of the same polarity so that the repulsing force betweensaid adjacent magnetic poles is operable to normally hold said onemember in said first position.
 3. An electric pushbutton switch asdefined in claim 2 in which said submagnetic pole plate extends theentire distance over which said first magnet member is reciprocallymoved relative to said Hall element on said pole piece.
 4. An electricpushbutton switch as defined in claim 3 further comprising means forguiding and limiting said relative reciprocal movement between saidfirst and second members.
 5. An electriC pushbutton switch as defined inclaim 4 in which said guiding and limiting means comprise a projectionon said one member and an elongated groove formed in said the othermember, said projection being in slidable engagement with said groove.6. An electric pushbutton switch as defined in claim 5, characterized inthat said first member is a base having an axial flat surface on whichsaid pole piece and said Hall element are mounted and a transverse flatsurface to which said second magnet member is secured, and that saidsecond member is a substantially cylindrical casing having an innersurface on which said first magnet member is mounted.
 7. An electricpushbutton switch as defined in claim 6 in which said casing has aclosed end adapted to be pressed down for the actuation of saidpushbutton, said base being adapted to be mounted on a support.